8 N + 5 P = 54
9 N + 6 P = 63
Fill in the blanks.
- 1 N = _____
- 1 P = _____
- 4 N + 5 P = _____
(a)
8 N + 5 P = 54 --- (1)
9 N + 6 P = 63 --- (2)
Make P the same.
LCM of 5 and 6 = 30
(1) x 6
48 N + 30 P = 324 --- (3)
(2) x 5
45 N + 30 P = 315 --- (4)
(a)
(3) - (4)
(48 N + 30 P) - (45 N + 30 P) = 324 - 315
48 N - 45 N + 30 P - 30 P = 9
3 N = 9
1 N = 9 ÷ 3 = 3
(b)
Substitute N = 3 into (1).
8 N + 5 P = 54
8 x 3 + 5 P = 54
24 + 5 P = 54
5 P = 54 - 24 = 30
1 P = 30 ÷ 5 = 6
(c)
4 N + 5 P
= 4 x 3 + 5 x 6
= 12 + 30
= 42
Answer(s): (a) 3; (b) 6; (c) 42
